Make method calls on null JSOs throw a NPE in DevMode.

Change-Id: If31642448f71704801b8fbe2c7387e5ddd4a80bc
Fix scalb to work with a scaleFactor of >=31 or <=-31.

The existing implementation uses an integer shift, which produces a
value of 0 for large shifts.

Change-Id: I36594ad83541a0869139b11da28485908080e0f2
Review-Link: https://gwt-review.googlesource.com/#/c/5322/
Set SO_REUSEADDR when starting Jetty

SO_REUSEADDR allows us to listen on TCP ports that are still in
TIME_WAIT status (i.e., someone else recently finished using it),
which is necessary for busy testing environments where many (or even
all) ephemeral TCP ports may be in this state.

The original comment says SO_REUSEADDR was disabled to prevent sharing
a port with another process.  However, it's actually SO_REUSEPORT that
allows multiple processes to listen on the same port.

Change-Id: Iafce162ef0398b7c935491a37a1b02cb0e48dfd8
Remove extra try catch for IE6/7 in entry function

According to comment and commit log this looks safe to remove:
https://code.google.com/p/google-web-toolkit/source/detail?r=7315

In general: We should avoid uncessary try catch clauses since
JavaScript JITs will not optimize such methods.

Change-Id: I45e73a800427afedc7fd5acd4dd06f40372aac40
Remove compiler modifications for IE6/7

Change-Id: I005beffa49a1877f7eacf34fe5b80d7b2faa3392
Merge remote-tracking branch 'upstream/master'